Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We hold the necessary qualifications to serve nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
How often should various gas detectors be calibrated and tested?
Instrument recalibration is typically every 1 year, determined by the submitting unit based on actual usage. During the secondary calibration process, if there are doubts about the instrument's test data, or if the main components of the instrument are replaced, or if recalibration is needed after repair.

Gas Detector Alarm Calibration Standard Requirements
Section 5.5 of the "Regulation for Calibration of Combustible Gas Detectors" (JJG693-2011) stipulates: The calibration cycle for combustible gas detection and alarm instruments: Generally, the calibration cycle of the instrument should not exceed one year. Instruments with suspected measurement data, instruments that have replaced major components, or instruments that have been repaired should be submitted for calibration promptly.
Section 3.5 of the "Regulations for the Use of Combustible Gas Detection and Alarm Devices" (SY6503-2000) stipulates: Combustible gas detection and alarm devices in use shall be calibrated periodically as required.
Occupational Health Service Establishment Standards (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be conducted regularly according to the manufacturer's specified time and procedures.
Section 3.4 of the "Code for the Use of Combustible Gas Detectors and Alarms" (SY6503-2000) stipulates: Combustible gas detectors and alarms for installation and use should have measurement instruments manufactured by an institution recognized for their **measurement** and **explosion-proof** performance.

Gas Alarm Meters Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
2. Relative Humidity: ≤85%
3. The working environment should not affect the normal operation of the instrument due to electromagnetic fields and interfering gases.
Inspection Gauges and Instruments
1) Certified Reference Material for Gases
The relative expanded uncertainty of the gas standard material does not exceed 2% (k=2).
2) Standard Gas Dilution Unit: Dilution Error of 1%.
3) Stopwatch: graduation not greater than 0.1s.
4) Flow Control: Flow range not less than 500 mL/min, flow grade not less than level 4.
5) Zero Point Gas: Purified compressed air.
6) Pressure Relief Valve: A pressure relief valve that is compatible with the calibration cylinder.
7) Gas Pipeline: Use气管 made of materials like polytetrafluoroethylene or stainless steel that do not affect the concentration of the measured gas.

Standard for verification and calibration of combustible and toxic gas detectors:
GB/T 50493-2019 "Design Standard for Detection and Alarm Systems of Combustible Gases and Toxic Gases in Petroleum and Chemical Industries"
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplaces
JJG693-2011规程 for Calibration of Combustible Gas Detectors and Alarms
Shenzhen ZhongNuo Testing Technology Co., Ltd. is an independent third-party institution specializing in electrical safety, electrical explosion prevention, gas alarms, and toxic gas detectors for regular inspections, metrological testing, and calibration services. We hold the necessary qualifications to address fire and explosion prevention issues for our clients.